Yonghai Dong1, Xiaodan Chen2, Yun Liu3, Yan Shu4, Ting Chen1, Lei Xu1, Meng Li1, Xihong Guan5. 1. Jiangxi Province Center for Disease Control and Prevention, Nanchang, China. 2. Jiangxi Provincial Cancer Hospital, Nanchang, China. 3. Cadre Wards of Neurology Medicine, Jiangxi Provincial People's Hospital, Nanchang, China. 4. The First Hospital of Nanchang, Jiangxi Province, Nanchang, China. 5. Remote Diagnosis Center, Jiangxi Provincial People's Hospital, Nanchang, China.
Abstract
OBJECTIVE: Whether low-serum vitamin E increases the risk of Alzheimer disease (AD) in older people remains inconclusive. This meta-analysis aims to synthesize evidence-based case-control studies to evaluate the association between serum vitamin E and the risk of AD. METHODS: Potentially relevant studies were selected through PubMed, Embase, Wanfang, Chongqing VIP, and China National Knowledge Infrastructure databases by using the core terms Vitamin E/alpha-tocopherol and Alzheime's disease/senile dementia/AD in the titles, abstracts, and keywords of the articles. The association between serum vitamin E levels and AD was estimated by using the weighted mean difference (WMD) and 95% confidence interval by adopting a random effects model. Heterogeneity was assessed by using Cochran Q test and I2 statistic. Forest plot was used to present the results graphically from meta-analysis. Publication bias was evaluated by using funnel plots and Egger test. RESULTS: We identified 17 studies that met the eligibility criteria. The studies included 2057 subjects with 904 AD patients and 1153 controls. The results indicated that AD patients had a lower concentration of serum vitamin E compared with healthy controls among older people (WMD = -6.811 μmol/L, 95% confidence interval -8.998 to -4.625; Z = -6.105, P < .001). Publication bias was not detected and sensitivity analysis performed by omitting each study, and calculating the pooled WMD again for the remaining studies indicated the results stable. CONCLUSIONS: Alzheimer disease is associated with a low concentration of serum vitamin E in older people. However, necessary prospective cohort studies should be conducted to determine the risk of serum vitamin E for AD in the future.
OBJECTIVE: Whether low-serum vitamin E increases the risk of Alzheimer disease (AD) in older people remains inconclusive. This meta-analysis aims to synthesize evidence-based case-control studies to evaluate the association between serum vitamin E and the risk of AD. METHODS: Potentially relevant studies were selected through PubMed, Embase, Wanfang, Chongqing VIP, and China National Knowledge Infrastructure databases by using the core terms Vitamin E/alpha-tocopherol and Alzheime's disease/senile dementia/AD in the titles, abstracts, and keywords of the articles. The association between serum vitamin E levels and AD was estimated by using the weighted mean difference (WMD) and 95% confidence interval by adopting a random effects model. Heterogeneity was assessed by using Cochran Q test and I2 statistic. Forest plot was used to present the results graphically from meta-analysis. Publication bias was evaluated by using funnel plots and Egger test. RESULTS: We identified 17 studies that met the eligibility criteria. The studies included 2057 subjects with 904 ADpatients and 1153 controls. The results indicated that ADpatients had a lower concentration of serum vitamin E compared with healthy controls among older people (WMD = -6.811 μmol/L, 95% confidence interval -8.998 to -4.625; Z = -6.105, P < .001). Publication bias was not detected and sensitivity analysis performed by omitting each study, and calculating the pooled WMD again for the remaining studies indicated the results stable. CONCLUSIONS:Alzheimer disease is associated with a low concentration of serum vitamin E in older people. However, necessary prospective cohort studies should be conducted to determine the risk of serum vitamin E for AD in the future.
Authors: Erin L Richard; Gail A Laughlin; Donna Kritz-Silverstein; Emilie T Reas; Elizabeth Barrett-Connor; Linda K McEvoy Journal: Nutrients Date: 2018-08-14 Impact factor: 5.717